ΔE 11.7, fair: the same colour family, but not a straight swap. Violet Vamp is more muted, cooler than Royal Purple.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Violet Vamp is more muted, cooler than Royal Purple.
The same difference applies the other way round: Royal Purple is more saturated, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Royal Purple on the colour wheel See Violet Vamp on the colour wheel
All matches: Royal Purple equivalents · Violet Vamp equivalents